1. Field of the invention
The present invention relates to a method for fabricating a semiconductor device, and more particularly to a method for fabricating a semiconductor device in which high dielectric material HfO2/HfSixOy is employed, wherein “X” is 0.4˜0.6 and “Y” is 1.5˜2.5.
2. Description of the Prior Art
According to Moore's law, semiconductor devices have been realized with the linewidth decrease of a MOSFET device and the thickness decrease of a SiO2 film. That is, improving the integration rate and the capability of semiconductor devices through such decreases in size have been achieved, first of all, by decreasing the linewidth of a MOSFET device and the physical thickness of a SiO2 film which is used as a gate oxide film.
However, when a SiO2 film having a thickness of 20 Å or less is used in the prior art, leakage current increases due to quantum mechanic tunneling of electrons, so that application of a device is impossible. Particularly, in a case of storage devices such as a memory and so forth, leakage current increase in a gate oxide film has a decisively bad effect upon the reliability guarantee of the devices, so development of new materials has been required.